kekalot

hi guys, looking for options on water purification, mostly only for cooking/drinking water. I have one of those counter top 3M thing here that is hooked up to the tap: the filters are 1750 baht each and they are supposed to be good for 2800 liters of water (costs 1.6 baht per liter) which in theory would give you roughly 7.5 liters of water per day.. we might drink 6-10 bottles of water per day from it which would amount to 4.5L and then the dogs get their water from there too but not 3 liters per day problem I am getting is that when I change the filter, it flows like the picture but only for a few days later and then it becomes absolutely slow. at this time I might be to 6 months and now it drips one drop per 2 seconds or so. it takes the whole day to fill the ice bucket I have put it in, then we put the water in the bottles and in the fridge. I think it's something to do with the very poor state of the water here sometimes.. sometimes the water is dirt dirty, like brown when the tanks are empty.. it seems to ruin the filtering very quickly and then we're back to drop drop. what I would like would be a better system. I've seen them online in Lazada whatever with the 3 filters system (or more) like this (just an example, don't care about this particular one): but all I want is quality filter that actually works (won't make us sick from drinking tap purified water), that has easy to purchase filters (don't mind purchasing 10 of them) and not too expensive hopefully and that is not going to cost me 1700 baht every 2-6 months from being gummed up (hard to avoid, i know). I can get bottles of water delivered with the truck here and it's at least 15 liters if not 20L for 15 baht which is cheaper than purifying it.. but it's certainly a chore to bring 20kg bottles upstairs (few floors up) and dump them in smaller bottles. If anyone has some experience with any good brands or any better ideas then i'm all ears.